Question

Think of the number, add $5$ and then multiply by $6$, the answer is $180$. What is the number?
A. $33$
B. $45$.
C. $25$
D. $40$

Answer 1

Hint: Let us think that the number we want to think is $x$ and then it is saying to add $5$ that is the number becomes $x + 5$ and again multiplies by $6$. So we get $6(x + 5)$ and this is equal to $180$. Now you can easily find the value of $x$ upon simplification.

Complete step-by-step answer:
Here we have to think of the number to which we add $5$ and then multiply by $6$ we should get $180$.
So let us assume that the number we want to think is $x$ and then it is saying to add $5$ that is the number becomes $x + 5$. Here $x$ is the original number which we had to find.
Now again the question says that we need to multiply the above result by $6$. Here the question is not saying to multiply $6$ by $x$ but by the new number we got. Here the new number is $x + 5$. So now again we get the new number after multiplying which we get $6(x + 5)$.
And in the question it is said that we think of a number $x$ and then it is said to add $5$ that is the number becomes $x + 5$ and again multiplies by $6$. So we get $6(x + 5)$ and this is equal to $180$.
So $6(x + 5)$$ = 180$
Upon simplification, we get that
$\Rightarrow$$6x + 30 = 180$
$\Rightarrow$$6x = 150$
Now divide by $6$ on both the sides, we get
$\Rightarrow$$x = \dfrac{{150}}{6} = 25$
Hence $25$ is the required number we need to think.

Option C is the correct answer.

Note: We can also do this by taking the options. For example: if we take the option $35$
So firstly we need to add $5$, so we get $35 + 5 = 40$
Now multiply by $6$, we get $40(6) = 240$$ \ne 180$
Hence this option is incorrect.
Now when we take $25$, add $5$, so we get $25 + 5 = 30$
Now multiply by $6$, we get $30(6) = 180$
Hence this option is correct.